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[World-wide status of hepatitis B vaccination 1998]
1Global Programme for Vaccines and Immunization, World Health Organization, Geneva.
Insights
The Hepatitis B (HB) vaccine is highly effective (85-95%) in preventing chronic carriers and reducing liver cancer. Global immunization efforts aim to protect children, but access in poorer nations remains a challenge.
Area of Science:
- Public Health
- Vaccinology
- Preventive Medicine
Background:
- The World Health Organization (WHO) recommended universal inclusion of the Hepatitis B (HB) vaccine in childhood immunization programs in 1991.
- By 1998, over 90 countries had integrated the HB vaccine into national programs, reaching approximately half the world's children and 70% of carriers.
- The WHO set a target to prevent 80% of new Hepatitis B virus (HBV) carriers in children by 2001 through routine immunization.
Purpose of the Study:
- To assess the effectiveness of the HB vaccine in preventing chronic carrier states.
- To evaluate the impact of widespread HB vaccination on public health outcomes, including liver cancer reduction.
- To identify challenges in achieving global access to the HB vaccine.
Main Methods:
- Population-based studies were conducted across multiple countries to determine vaccine efficacy.
- Analysis of national immunization program data to track vaccine uptake and coverage.
- Review of epidemiological data on HBV carrier rates and liver cancer incidence in immunized populations.
Main Results:
- The HB vaccine demonstrated 85% to 95% effectiveness in preventing the chronic carrier state in population-based studies.
- Studies in Taiwan showed a direct reduction in liver cancer among immunized children.
- Significant progress has been made in global vaccine adoption, but equitable access remains an issue.
Conclusions:
- The HB vaccine is a highly effective tool for preventing chronic HBV infection and reducing liver cancer incidence in children.
- Widespread implementation of routine childhood immunization programs is crucial for controlling HBV transmission.
- Developing sustainable financial mechanisms is essential to ensure all children, particularly in low-income countries, benefit from this life-saving vaccine.
Abstract:
In 1991 WHO recommended that all countries include HB vaccine into their routine childhood immunization programmes. By 1998, more than 90 countries have included HB vaccine as routine antigen in their national programmes. These countries include about half of the world's children and about 70% of the world's carriers. The WHO target is to prevent 80% of new HBV carriers in children by the year 2001 by adding the vaccine into routine immunization. The vaccine has proven to be 85% to 95% effective in preventing the chronic carrier state in population based studies from many countries. Studies in Taiwan have already shown a direct reduction of liver cancer in immunized children. The major remaining problem is to develop financial mechanisms to allow the children in the poorest countries to benefit from this important vaccine.